This invention relates to audio transducers and more particularly to planar electromagnetic loudspeakers.
In the audio transducer field, there are numerous diverse types of sound reproduces. These include, but are not limited to, magnetically driven conical or planar transducers, electrostatically driven planar transducers, foam radiators (driven by electromagnetic force) plasma jet or air ionization devices, and magnetically squeezed pleated metal plate devices. In addition, there are many other transducers that convert audio signals to sound. Planar active diaphragm transducers are generally acknowledged as being the most capable of accurate sound reproduction. However, although accuracy is high for the planar diaphragm transducer, there are other limitations which have not allowed this form of transducer to become commercially feasible.
One form of planar transducer, the electrostatic planar transducer, requires high voltages (which must be provided by special amplifiers or transformers), and is prone to arcing or other malfunctions. Generally, electrostatic planar transducers operating in standard atmosphere cannot produce high sound pressure levels without breakdown. Another prior art form, the electromagnetic planar transducer, is extremely inefficient in that it requires relatively large amounts of power to produce acceptable listening levels.
Accordingly, it is an object of this invention to provide an improved active diaphragm transducer.
It is another object to provide a relatively high efficiency planar diaphragm loudspeaker.